1. Field of the Invention
The present invention relates to a golf club head, and more specifically, a "wood" type head.
2. Discussion of Background and Relevant Information
Currently, the clubs used by golfers when striking the ball from the "tee" or starting zone to propel the ball over long distances are known as "woods". Originally, "woods" were constructed entirely of wood materials such as persimmon or other varieties. These clubs are still appreciated by many players, but they are not very tolerant, given the low density of the material utilized and its homogeneous distribution behind the impact surface of the club head.
The "wood-metal" club appeared in order to alleviate this disadvantage by keeping the form of the wood, but with a head constructed entirely of steel. Given the high density of the material utilized and the mass constraints imposed, the wood-metal generally comprises a hollow steel head, generally obtained by cire perdue casting/lost wax process. In this type of construction, the mass is mainly distributed at the periphery of the impact surface, and imparts the club with a tolerance that is significantly greater than that of the conventional "woods". This tolerance concerns both the starting angle of the ball, also known as "loft" angle defining the vertical trajectory of the ball, as well as the deviation of the ball, i.e., the lateral trajectory of the ball.
A first disadvantage of the wood-metals concerns the unpleasant sensations felt by the players during impact, due to the metallic contact with the surface on the ball.
Another disadvantage arises from the fact that the stiffness of the steel impact surface, the thickness of which must be sufficient to support the shock of a hit, is not optimum. It can be demonstrated that a decrease in the rigidity of the surface increases the speed of restitution, thus generating a greater flight distance. Therefore, one can demonstrate that the rigidity of the surface depends upon the thickness of the impact surface and the modulus of elasticity of the material. At a given modulus of elasticity, the decrease in rigidity is thus directly related to a decrease in the thickness of the surface. Therefore, it presently appears that the optimum point of rigidity of the impact surface of a "wood-metal" corresponds to a thickness that is too low, at less than 3 mm, bringing about its irreversible deformation.